Low temperature fill-and-dump dishwashing machines are widely used in North American commercial and institutional eating establishments, such as delis, bars, fast food chains, private owner restaurants and cafeterias. Low temperature fill-and-dump dishwashing machines can take many forms such as under-counter machines, door ‘pass through’ machines, conveyor machines, or flight machines. Regardless of their form, all of these low temperature fill-and-dump machines have the same life cycle of water flow during the wash and rinse/sanitize cycles. At the beginning of a wash cycle for a low temperature fill-and-dump machine, detergent is dispensed into the machine which is filled with pre-heated water. Actuation of the low temperature fill-and-dump machine to start the wash cycle can take place, for example, by opening and shutting the door of a pass through machine, or via a sensing mechanism that detects the introduction of a rack into the machine.
Following the wash process, the built-in machine drain opens to ‘dump’ the wash solution containing the detergent to a holding tank or an outside drain. Just before the machine drain closes, the water fill is actuated thus creating a flush cycle, after which the drain closes. Fresh water, rinse aid, and sanitizer are then dispensed into the machine in the rinse cycle, and following completion of the rinse cycle, the machine operation shuts down until it is again actuated. The rinse water fill becomes the water for the next set of ware to be washed, after which it is once again drained out. The water filling at the beginning of the rinse cycle and water dumping at the end of each wash cycle is what makes a professional washing machine ‘low temperature fill-and-dump.’
Low temperature fill-and-dump machines use a sanitizer, such as chlorine or iodine, to sanitize the dishware before it is removed from the machine. The use of a chemical sanitizer is mandated for low temperature fill-and-dump machines that do not achieve sufficient temperatures (around 80° C.) for hot water sanitization to be effective within the time frame in which the sanitization takes place, typically 15-20 seconds. Low temperature fill-and-dump machines operate at a temperature of from about 49° C. to about 60° C. Unfortunately, the mandated sanitizer reacts negatively with most detergent enzymes that are present for effective dishware cleaning.
The art recognizes the benefits of enzyme-based detergents for use in commercial dishwashing machines that sanitize using hot water, but is silent on enzyme-based detergents for use in low temperature fill-and-dump machines that are required to use chemical sanitizers. Therefore, a need exists for a cleaning system that provides for enzymatic cleaning in a chemical sanitizer, low temperature low temperature fill-and-dump machine.